Lunar Eclipse Diagram
This shows the geometry of a lunar eclipse. When the Sun, Earth, and Moon, are precisely aligned, a lunar eclipse will occur. During an eclipse the Earth blocks sunlight from reaching the Moon. Earth creates two shadows: the outer, pale shadow called the penumbra, and the dark, inner shadow called the umbra. The eclipse is noticeable once the Moon enters the umbra.
Image Number: WEB11715-2010
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